Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #16  
Old 02-20-2014, 11:20 PM
JamesDean's Avatar
Electrical Engineer
 
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,038
they are also called 'switch over valves'.

They are electrically controlled vacuum switches.





__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k
Reply With Quote
  #17  
Old 02-21-2014, 12:15 AM
Registered User
 
Join Date: May 2004
Location: Natchez MS and Dallas TX
Posts: 355
Quote:
Originally Posted by crazy4diesel View Post
What's a change over valve, and does my car have them? 83 300TD.
IIRC its function is to keep the idle the same rpm when the ac is turned on i.e. if you didn't have one your idle would drop some when the ac compressor turns on and raise some when the ac compressor goes off. The valve is electrically controlled to add some air or vacuum to the fuel injection unit which causes more fuel to be injected. This answer is worth what you paid for it.
__________________
85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K
Reply With Quote
  #18  
Old 02-21-2014, 08:01 AM
Registered User
 
Join Date: Jan 2009
Location: Western MA
Posts: 107
On my 85 300sd there is a bank of them on the passenger side behind the center console. They use electrical signals from the CCU to control the vacuum pods. In my case the keg room flap changeover unit was not functioning.
__________________
1985 300SD 99K
Reply With Quote
  #19  
Old 02-21-2014, 10:37 AM
JamesDean's Avatar
Electrical Engineer
 
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,038
Quote:
Originally Posted by jimandsuzy View Post
IIRC its function is to keep the idle the same rpm when the ac is turned on i.e. if you didn't have one your idle would drop some when the ac compressor turns on and raise some when the ac compressor goes off. The valve is electrically controlled to add some air or vacuum to the fuel injection unit which causes more fuel to be injected. This answer is worth what you paid for it.
On the 617 there is no electronic influence over the idle speed.

The switch over valves referenced in this thread are for controlling the various vacuum pods for the HVAC system.

In the 84/85 617 cars there is a microswitch on the top of the valve cover that will cut out the a/c when it is hit.

I believe you are thinking of the idle air control valve and the idle control system that is found in the gasoline powered cars. On there 617 diesel there is no equivalent that I am aware of.

__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 07:50 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page